Investments (Credit Quality of Agricultural and Residential Mortgage Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Mortgage Loans, Gross	$ 79,860	$ 84,344
Mortgage Loans in Process of Foreclosure, Amount	70	103
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	697
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	465
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,331
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	603
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	287
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,813
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 11,196	13,782
Loans Receivable Residential Mortgage Percentage	100.00%
Residential Mortgage Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 695
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	460
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,277
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	583
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	283
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,448
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 10,746
Loans Receivable Residential Mortgage Percentage	96.00%
Residential Mortgage Loans | Nonperforming (1)
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 2
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	54
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	20
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	365
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 450
Loans Receivable Residential Mortgage Percentage	4.00%
Agricultural Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 2,812
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,372
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,165
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,754
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	962
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,958
Financing Receivable, Revolving	1,088
Mortgage Loans, Gross	$ 18,111	$ 18,128
Loans Receivable Agricultural Mortgage Percentage	100.00%
Agricultural Mortgage Loans | Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 2,483
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,989
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,855
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,549
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	922
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,325
Financing Receivable, Revolving	968
Mortgage Loans, Gross	$ 16,091
Loans Receivable Agricultural Mortgage Percentage	88.80%
Agricultural Mortgage Loans | 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 329
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	383
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	234
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	205
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	40
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	579
Financing Receivable, Revolving	120
Mortgage Loans, Gross	$ 1,890
Loans Receivable Agricultural Mortgage Percentage	10.40%
Agricultural Mortgage Loans | 76% to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	11
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 11
Loans Receivable Agricultural Mortgage Percentage	0.10%
Agricultural Mortgage Loans | Greater than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	76
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	43
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 119
Loans Receivable Agricultural Mortgage Percentage	0.70%